Cow magazine ad more persistent than I'd like

Cow magazine ad more persistent than I'd like
by Joe Murray on Jun 10, 2006 at 3:00:51 am

I think it's great that the great team at the Cow has decided to publish a magazine. But I get the "pardon the interruption" advertisement much more often than the ad says I should. Sometimes 3 times within a Cow surfing session of less than an hour. Is there any way to permanently identify an IP address as having subscribed or chosen not to, so this ad would be "smarter" and not get in the way so much?